We conducted a pilot-scale study at a research facility in southeastern Connecticut to assess the effects of leachfield aeration on removal of nutrients and pathogens from septic system effluent. Treatments consisted of lysimeters periodically aerated to maintain a headspace O(2) concentration of 0.209 mol mol(-1) (AIR) or vented to an adjacent leachfield trench (LEACH) and were replicated thre...

A wireless sensor network is composed of a large number of sensor nodes that are densely deployed in a phenomenon or very close to it. The lifetime of sensor nodes shows a strong dependence on battery lifetime. Clustering provides an effective way for prolonging the lifetime of a wireless sensor network. Therefore, Clustering techniques are used to distribute the energy consumption among nodes ...

Energy efficient is the most important issue that must be solved in designing a qualified routing protocol for wireless sensor networks (WSNs) is how to save sensor node energy while meeting the needs of applications/users as the sensor nodes are battery limited. . There are number of various routing protocols have been proposed to optimize the efficiency of WSNs. From these protocols, cluster ...

The hierarchical routing protocol LEACH (Low Energy Adaptive Clustering Hierarchy) is referred to as the basic algorithm of distributed clustering protocols. LEACH allows clusters formation. Each cluster has a leader called Cluster Head (CH). The selection of CHs is made with a probabilistic calculation. It is supposed that each non-CH node join a cluster and becomes a cluster member. Neverthel...

Clustering is an efficient approach to capitalize the energy of energy constraint sensor nodes in wireless sensor networks. Clustering schemes do not guarantee formation of clusters with equal number of nodes. So data frames transmitted by the nodes vary. TDMA schedule of nodes of smaller cluster is smaller than others that results more number of data frames and hence more energy consumption. T...

1 This work was supported by MEXT/JSPS Grant-in-Aid for Scientific Research(C) Grant Number (22500071). Abstract Sensor networks consisting of nodes with limited battery power and wireless communications are deployed to collect useful information from the field. Gathering sensed information in an energy efficient manner is critical to operate the sensor network for a long period of time. LEACH ...

There is neither a prescribed format nor a rigid sequence of testing to follow for the assessment of health and environmental effects of chemicals. Conventional animal toxicity tests plus medical surveillance and monitoring of exposed human populations will provide knowledge of the biological effects of chemicals and assurance that they can be handled safely. Useful information also can be deri...

ــ ـ ـ The wireless sensor networks suffer from the problem of energy consumption, so it has been used several protocols to avoid this problem, the best of these protocols is a LEACH protocol which works to reduce the energy consumption of the network. On the other hand, LEACH protocol suffers from the problems of accelerated the dead nodes as well as the short duration of the network lifetime....